Leverage system



Oct. 17, 1950 E. c. NEAL 2,526,263

LEVERAGE SYSTEM Filed Aug. 9, 1945 I 3 Sheets-Sheet 1 lag .2 22% M? Oct. 17, 1950 E. c. NEAL 2,526,263

LEVERAGE SYSTEM,

Filed Aug. 9, 1945 3 Sheets-Sheet 2 Oct. 17, 1950 E. c. NEAL 2,526,263

LEVERAGE SYSTEM Filed Aug. 9, 1945 3 Sheets-Sheet 5 %H|]' 14 50 i 2 J4 7 J/ZMEIZZZ? E //Z65ZEC$/ QZ Patented Oct. 17, 1950- LEVERAGE SYSTEM I Ernest C. Nal', Chicago,.-Ill., assignor of one-half o to Elmer Brandell, Chicago, Ill.

' ntimalarial-1e 9,1945, SerialNo. 609,769

This invention relates in general to power multiplying leverage systems and has more particular reference to a compound leverl mechanism providing for the movement of an actuated lever member about its fulcrum, by the application of force to a fulcrum remote portion of the lever member, through the medium of a I drivinglever'having moving contact with a surface of the lever member at said remote portions, thepresent application, relating especially to the combination of the leverage system with ratchet 'mechanism in. power tools, and comprisinga continuation in part of copending application for United States Letters Patent, Serial No. 520,400, 'filed January 31, 1944, now Patent 2,385,835, issued October 2, 1945, for-lever construction.

An important object of the invention is to provide compact and efiicient means for imparting relative movement in an actuated lever, through the application of force applied to a fulcrum remote portion of the lever; a further object being 'to apply lever moving force through the action of a driving lever whereby to accomplish maximumpower, multiplication at a minimum expenditure of effort; a still further object being to so arrange and mount the driving lever that maximum power multiplication, may be accomplished during a selected or desired portion of its operating stroke.

Another object is to apply force to the actuated lever by means of a roller or other power applying element on the driving lever and to so mount the levers that the rojller may alter its point of engagement on pne of the levers, with respect to the fulcrurrr of-said lever, in order to I determine maximum power multiplication during a desired portion of the operating'stroke of the mechanism.

Another important object is to so arrange the driving and driven levers that the power transfer roller, during the performance of a power stroke,

may roll, substantially without frictional loss, first in one direction andthen in the reverse direction on one of the levers with respect to the fulcrum of such lever.

Another important object is toutiliu the movement imparted in the driven lever for the operation of a pawl and ratchet mechanism; a further object being to incorporate the lever driven pawl and ratchet in power tools of various sortsincluding rod and cable cutters, jack mechanisms and other tools and devices incor- 2 objects, advantages, andinherent functions the invention will become apparent as the in- ,vention is more fully understood from the folporating pawl and ratchet mechanisms for power lowing description, which, taken in conjunction with the following drawings, discloses a preferred embodiment of the invention.

Fig. 1 is a fragmentary side view showing a pawl and ratchet power transmittingmechanism embodying power multiplying levers incorporat ing the present invention;

Fig. 2 is a view showing a modified form of-thepower multiplying levers;

Fig. 3 is a view showing the levers of Fig. 2 used for pawl driving purposes;

Fig. 4 is an elevation view of a rod and cable cutter embodying pawl and ratchet power transmitting means actuated by power multiplying levers in accordance with the present invention;

Fig. 5 is a view in vertical section-through a lifting jack embodying the present invention;

Fig. 6 is a view taken substantially along the line 66 in Fig. 5; and V Fig. '7 is a sectional view taken substantially along the line 'I! in Fig. 5.

To illustrate the invention the drawings show, in each case, a support frame II carrying a pair of cooperating levers I2 and I3 pivoted on the frame II, the lever I'2 having a fulcrum pivot I4 and the lever I3 a fulcrum pivot I5 supported in the main frame II. The lever I2 comprises a driving lever preferably adapted for manual operation about its fulcrum pivot I4, the lever I3 being driven about its fulcrum pivot I5 in response to the driving movement of the lever I2".

To this end the lever I3 has a fulcrum remote bearing portion or surface I 6 in position to receive thrust imparted by the lever I2. The lever I2 is provided with a thrust member I! in position to bear upon the surface IS. The thrust member If preferably comprises a roller mountresult of power applicationat the fulcrum remote end of the lever I2 and transferred to the lever I3'jthrough the transfer element or roller The bearing surface- Ij6'of the lever |"3{'iS1'C- .motefromthe fulcrum pivot I5; and thelevers I2 and I3 are so mounted that the bearing portion I6 normally extends on the side of the fulcrum pivot I4 remote from the fulcrum pivot I5. The fulcrum pivot I4 of the lever I2 thus lies more or less intermediate the bearing portion I6 and the fulcrum pivot I5. The parts are also preferably arranged so that the area of .ate driving surface 24 on the lever I3. nately, the lever I3 may be drivingly connected contact between the surface I6 and the member I1, at the commencement of an operating stroke, lies on one side of the plane which passes through the axes of the lever pivots I4 and I5, such area of contact moving during the performance of a power stroke, through such plane of pivots, to the opposite side thereof.

It will be seen that the member I'I, during the performance of a power stroke, will initially travel on the surface I6 in a direction away from the fulcrum pivot I5, thus initially increas- I5, and the shape of the lever I3 including the shape and inclination of the surface I6, in order to, accomplish maximum power multiplication at the end of the stroke. Usually, however, it is desirable to accomplish maximum power multiplication during the medial portions of the operating stroke where maximum power multiplying effect is ordinarily desired.

The driven movement of the lever I3 may, of course, be employed to accomplish any desired work. As shown in Figs. 1, 3, 4 and 5, the movement of the lever may be utilized to drive a pawl for the operation of a suitably toothed pawl driven member. This driven member, as shown in Fig. 1, may take the form of a ratchet wheel driven by a pawl I9. In the Fig. 3 embodiment, a pawl 3I9 serves to drive a ratchet wheel 320. The arrangement shown in Fig. 4 comprises a ratchet wheel 420 actuated by a pawl 4 I 9,,

while, as shown in Fig. 5, the toothed element may comprise a rack 520, driven by a pawl -5I9.

As shown in Figs. 3, 4 and 5, the driving pawl may be connected directly on the lever I3, as by means of a suitable pivot pin 2|, mounted on the lever, or, as shown in Fig. l of the drawings, the pawl I9 may be pivoted, as at 2|, on an intermediate pawl carrying lever 22 having a thrust receiving member, such as a roller 23, at an end thereof in position to engage a preferably arcu- Alterwith the lever 22 by means of a connecting link or other driving element.

The various elements of the mechanism may be biased, as by gravity, by springs, or by the resistance of work to be accomplished, toward aninitial or starting position, As shown in Fig. 1

,of the drawings, the lever 22, which is pivoted in the frame II, is provided with spring: means 25, operatively connected between the lever 22 and the frame II, which yieldingly urges the .lever 22 toward a retracted, initial or starting position. When in such position, the pressure of the roller 23 upon the lever I3 urges it and also the operating lever I2 toward the initial or 4 ence of the spring 25, and will move the pawl I9 to drive the ratchet wheel in the direction of th arrow.

During the operating stroke of the mechanism, the roller [1 may travel outwardly of the pivot I5 on the surface I'6 thereby increasing the power multiplying effect of the leverage mechanism.

until the roller reaches its maximum displacement outwardly of the fulcrum pivot I5, which will occur approximately when the axes of the pivots I4, I5 and I8 lie in acommon plane, the

distance between the roller and the fulcrum pivot I5 decreasing after the axis of the roller passes through such common plane. -The pawl and ratchet mechanism and the lever 22, also the arrangement of the driving connection between the levers I3 and 22, may be arranged so that the mechanism accomplishes maximum power multiplication when the pawl has shifted the ratchet 20 320, 420 or 520, as the case may be, through a desired displacement, suchas a ratchet wheel displacement necessary to advance the wheel through the pitch distance between its teeth in order to allow operation of a holding pawl, shown at 26, 26 and 26 in Figs. 3, 4 and 5 respectively; 6

As shown in Fig. 3 of the drawings,

I3 and extends thence in position to, drivingly cooperate with the ratchet wheel-320', rotatably mounted in the frame II. The frame II may also carry the holding pawl 26 suitably biased toward operative engagement with theratchet wheel. A spring 21 maybe connected between a pin 28 on the lever I3 and a mounting pin 29 on the frame I! to normally urge the lever I3 and its cooperating driving lever I2 toward the retracted position shown in Fig. 3.

By moving the drivinglever I2 in a counterclockwise direction on its fulcrum pivot I4, the transfer element or roller I! may be caused to press upon the bearing surface I6 and roll thereon initially outwardly of the pivot I5 to turn the lever I3 in a counter-clockwise direction on said pivot I5. Such movement of the lever I3 may terminate when it reaches the dotted line position, shown in Fig. 3, in which position the pawl 3I9 will have turned ratchet wheel 320 through a displacement sufficient to allow the holding pawl 26 to drop into and'lock with the next succeeding tooth of the ratchet wheel. Suitable spring means 35 may be associated with each of the pawls (H9 and 26 in order to yieldingly urge the same into operative engagement with the ratchet wheel 320. t

The power multiplying leverage and ratchet arrangement of the present invention, as shown in Fig. 4 of the drawings, may be applied to advantage in a rod or cable cutter in which the frame I I forms acutting jaw 30, while the ratchet wheel 420 forms a cooperating cutting jaw 3|, the parts being connected together for pivotal movement about a pivot pin' 32 and normally urged toward jaw opeuposition, as by means of a spring 33 bearing at its (opposite ends respectively on members I I and 420. To stop the members I I and 420 in jaw open position, cooperating stops, comprising a pin 30 on one member and a cooperating projection 3I on the other, may be provided. The frame II in this embodiment may be provided with an upstanding .handle34 so that by grasping the handle 34 the device may be steadied in operative position. The driving lever I2 also forms a handle extending generally adjacent thehanclle 34. 7 By drawing the iulcrum I the pawl 3! is pivotally connected directly on the lever remote end of the "handle I2 away from the handle 34, the lever I2 will be turned on its pivot I4 in' a clockwise direction, viewing Fig. 4, thus causing the roller IT to press upon and ride along the surface I6 initially in a direction away from the pivot I5, thereby turning the lever I3 in a clockwise direction on its pivot I with progressively increasing force until the roller passes through the plane of the pivots I4 and I5. Re suiting movement of the lever I3 in a clockwise direction, viewingFig'. 4, will cause the pawl 4I9,

pivoted thereon, to engage the teeth of the ratchet member 52 0 and turn it in a counterclockwise direction onthe pivot 32, thereby forcing the cutting jaw 31- toward the cooperating jaw- 30-. The-parts. may be soarranged that the pawl M a-during an operating stroke of the lever I2, will advance thev member 420, against the inframe kt, may beuprovided to prevent retrogressivie movement of the member' flfl under the influenceqof the, spring 33.

Springmeans .35 -may be provided on the frame II to normally urge the pawls M9 and 26' inya direction to engage the teeth of the ratchet member; 620. provided to cooperate with the pawls M9 and 26, for; the purpose of releasing the same against the influence of the spring means to allow the cutting member 429; to return to an initial or starting position, under the influence of the spring- 33after the jaws3ll and 31 have been completely closed in the performance of a cutting operation, as a. result of repeated strokes of the handle I 2.

As shown in Fig. 5, the frame II forms a jack housing providing. a channel in which the rack member 520, is longitudinally movable in cooperation with aholding pawl 26 and the pawl 5I9 pivoted, as at ZI, onthe lever I3. Spring means 35?- may be employed to resiliently urge the driving and holding. pawls 5I9 and 26. toward operative engagement withthe teeth of the rack member 520.. 1

' In this. embodiment the holding pawl 26 is of splitc'onfiguration being pivoted in the frame II, as at 31; on opposite sides of 'therack member. By operating the handle I2, the pawl 5I 9 may be moved upwardly in the frame II in engagement' with the rack 529', the holding pawl 26 snapping over the teeth of the rack member.

In this connection the lifting pawl 5I9 may be.

withdrawn from the rackand guided'into a notch II in the holding pawl. Thereupon the holding pawl'may, be withdrawnfrom the rack by lifting.

action of the lifting pawl. in the notch. A1-' ternately, a step-by-step rack lowering operation,

under pawl control, may be accomplished by rocking the handle IZ-and SeIectiVely withdrawing the, pawls from the rack by manual operation of the pins 38 and 39. If desired; adjustable pawl guid A control lever 36.- may also be ing' means may be provided for retracting the pawls selectively and automatically in the per-' formance of a step-by-step racklowering opera-' tion.

,Asshown in Figs. 4-7 the lever I2 may have a split or forked end comprising the lugs 43 between which the roller I'I is'mounted. The frame II, also, may be provided withspaced walls 44 forming mounting lugs 55 for receiving the pivot pin It, which is also mounted in the lugs 43, As more particularly illustrated in Figs. 6 and 7, the walls 44, also, may be provided with aligned embossments 46, inwardly of the' lugs 45, and threaded to receive mounting. plugs M; The embossments 4B are cut away, as at 48, in the side thereof'facingtowardthe lugs 45. The pivot pin I5 may comprise a member, force-fitted in a suitable opening formed in the lever I3, said member having opposite ends projecting on opposite sides of the lever to a length permitting insertion of the lever I3 with attached pivot pin I5, between the lugs 45 and through the opening 48, to centered position with respect to the.

threaded bosses 46. After the lever I3 has thus been mounted, the mounting plugs ti may be threadedly engaged in the bosses 45 to form bearings for the opposed ends of the pivot pin I5. The mounting plugs may be secured in position, as by thecotter-pins 49'. After assembly of the lever I3, the lever I2 may be pivotally mounted on the lugs 45 by. driving the pivot pin I4 through said lugs 45 and the ears 43.

The lever I3, as shown in Figs. 6 and 7; may be formed with a split end forming ears 5!] between which the pawl I9 may be pivotally mounted, as on the pin 2i; and in order to obtain maximum leverage, the pin 2| is preferably disposed as closely as possible to' the pivot pin I 5, which may be cut away, as at 51 and 52., in its side facing the pin 2I to allow the pin and the pivoted end of the pawl I9 to be mounted on the lever I3.

In the embodiment shown in Figs. 4 and 5 it is preferable, as a matter of convenience, to link the lever I3 to the lever I2 in order to insure retraction of the lever iii to the initial or starting position. To this end, the lever I 3 may be cut out on one side, as at 53, to receive the end of a tie link 54. The link has an elongated slot 55, at oneend, loosely receiving a pin 56 in the lever I3, the other end of the link being pivoted on the lever l2 as on the roller pivot I8. This link will draw the lever I3 to an initial or starting position with; the surface It in engagement with the roller I'I,. as shown in Figs. 4 and 5, but will idle the pin 56 in the slot 55 during a power stroke.

It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and it is obvious. that numerous changes may be made in the form,v construction and arrangement of the several. parts without departing from the spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing 'member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said power lever,'to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction initially outwardly of said lever pivot for power multiplying purposes.

I 2. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on the said frame, a driving pawl operatively associated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot, at the side thereof remote from said lever pivot, in position to engage said bearing member and to be moved thereby, during a power stroke of said power lever, from a position engaging said bearing member on one side of the plane including the axes of said fulcrum and lever pivots, to a position engaging said bearing member on the other side of said plane whereby to drive said ratchet member through said pawl.

3. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on the said frame, a pawl operatively associated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon, said lever member having an elongated bearing surface extending adjacent said fulcrum pivot, on the side thereof remote from said lever pivot, in position to engage and receive thrust from said bearing member, said bearing surface being movable during a power stroke of said power lever, from a position engaging said bearing member on one-side of the plane including the axes of said fulcrum and lever pivots, to a position engaging said bearing member on the other side of said plane whereby to apply maximum driving effect to said ratchet member, through said pawl, during medial portions of the operating stroke of said power lever.

4. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on the said frame, a driving pawl operatively associated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot, and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being d rn" r powe stroke of said lev r. to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction initially outwardly of said lever pivot for power multiplying purposes whereby to drive said ratchet member through said driving pawl, and a holding pawl for holding the ratchet member against retrogressive movement.

5. A device of the character described comprising a frame, a rack bar movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to drive said rack bar through said driving pawl, and a holding pawl for holding the rack bar against retrogressive movement.

6. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement, about a lever pivot on said frame, a driving pawl operatively associated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member'having 'an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to drive said ratchet member through said driving pawl, a holding pawl for holding the ratchet member against retrogressive movement, and detent means for guiding said pawls out of operative engagement with said ratchet member.

7. A device of the character described comprising a frame forming a cutting jaw, a ratchet member movably mounted on the frame forming a cooperating cutting jaw, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operativelyrassociated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn saidlever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to move a-szaeea said'ratchet member on said frame in a direction to relatively close said jaws.

8. A device of the character described comprising a frame forming a cutting jaw, a ratchet member movably mountedon the frame forming a cooperating cutting jaw, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said ratchet member and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power leverhaving abearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot .in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to move said ratchet member on said frame in a direction to relatively close said 7 jaws, and. spring means operatively connected between said frame and ratchet members to yieldingly urge said ratchetmember and frame relativelytoward jaw open position.

9. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said ratchet member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever, member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes, said driving pawl being mounted on an auxiliary lever pivoted on said frame and drivingly connected with said lever member.

10. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turningmovement about a lever pivot on said frame, a driving pawl operatively associated with saidratchet member, a power lever having an, end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having 1 an elongated bearingsurface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a "direction outwardly of said lever pivot for power multiplying purposes, said-driving pawl being mounted on an auxiliarylever pivoted on said frame, said lever memberhaving a bearing cam surface in position to drivingly engage said auxiliary lever.

11. A device of the character described comprising a frame, a ratchet member movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said ratchet member, a power lever said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of saidlever pivot for power multiplying purposes, said driving pawl being mounted on an auxiliary lever pivoted on said frame and drivingly connected with said lever member, and spring means yieldingly urging said auxiliary lever toward retracted position.

12. A device of the character described comprising a frame, a rack bar forming a lifting jack movably mounted on'the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative ,turning movement about a fulcrum pivot on said frame and spaced from said lever'pivot, said power lever having a'bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multi lying purposes whereby to raise said rack bar in said frame.

13. A device of the'character described comprising a frame, a rack bar forming a lifting jack movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operamovement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereonadjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, and a holding pawl pivoted on the frame in position to engage said rack bar and prevent retrogressive movement of the same.

14. A device of the character described comprisinga frame, a rack bar forming a lifting jack movably'mounted on the frame, a lever member connectedfor relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame 1 having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, a holding pawl pivoted on the frame in position to engage said rack bar and prevent retrogressive movement of the same, and

spring means normally urging said pawls into operative engagement with said rack bar.

15. A device of the character described comprising a frame, a rack bar forming a lifting jack movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and saidlever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, a holding pawl pivoted on the frame in position to engage said rack bar and prevent retrogressive movement of the same, spring means normally urging said pawls into operative engagement with said rack bar, and selectively positionable pawl guiding means on said frame for guiding said pawls in a jack lowering operation.

16. A device of the character described comprising a frame, a rack bar forming a lifting jack movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, and a holding pawl pivoted on the frame in position to engage said rack bar and prevent retrogressive movement of the same, said holding pawl having an operative rack engaging head adapted to straddle the driving pawl and engage the rack on opposite sides of the driving paw 17. A device of the character described comprising a frame, a rack bar forming a lifting jack movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member-thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, said lever member carrying said lever pivot extending therefrom on opposite sides thereof and said frame having spaced walls formed with aligned embossments for supporting said lever pivot, said embossments having lateral gates formed therein to allow assembly of the lever pivot radially into the embossments, and bearing members insertable axially in said bosses to journal said lever pivot therein.

18. A device of the character described comprising a frame, a rack bar forming a lifting jack movably mounted on the frame, a lever member connected for relative turning movement about a lever pivot on said frame, a driving pawl operatively associated with said rack bar and drivingly connected with said lever member, a power lever having an end connected for relative turning movement about a fulcrum pivot on said frame and spaced from said lever pivot, said power lever having a bearing member thereon adjacent said fulcrum pivot and said lever member having an elongated bearing surface extending adjacent said fulcrum pivot in position to engage said bearing member, said bearing member being adapted, during a power stroke of said lever, to bear upon said surface to turn said lever member on said lever pivot and to ride said surface in a direction outwardly of said lever pivot for power multiplying purposes whereby to raise said rack bar in said frame, said lever member carrying said lever pivot extending therefrom on opposite sides thereof, said lever pivot comprising a pivot pin, means for supporting said pivot pin in said frame on opposite sides of the lever member, said pawl being mounted on a support pin in said lever member adjacent said pivot pin, one of said pins being relieved on one side to receive the other pin in closely juxtaposed and interfitting relationship to thereby reduce the lever arm between said pins.

' ERNEST C. NEAL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS' Schwerin Feb. 6, 1934 

